In a medical emergency, it is frequently necessary for the medical practitioner to insert a breathing tube into the patient's trachea so that he or she can be ventilated. The tube must enter the larynx and pass through the opening between the vocal cords. Care must be taken during insertion to prevent the tube from entering the esophagus.
Some patients present more difficult airway access than others. Medical experts have classified airways into four different types. Type I is easily accessible and type IV is the most difficult. Airways need to be protected in unconscious patients, as well as in those of motor vehicle accident victims who may have suffered an unknown fracture of the cervical spine. This presents a special challenge to the medical practitioner. In such situations, if one were to extend the neck in the usual fashion, that is, in such a way that one can visualize the vocal cords by using a direct laryngoscope in order to insert the endo-tracheal tube, one could injure the spinal cord, causing severe paralysis or even death. Moreover, endo-tracheal tube insertion must be accomplished in less than 4 minutes to avoid brain death. Prolonged intubation procedure time can result in various degrees of brain injury.
Accidental placement of an endo-tracheal tube, whether it is inserted nasally or orally, in the esophagus rather than in the trachea is a possibility because of the natural curvature of the orpharynx. Such placement can result in patient hypoxia, varied degrees of brain damage and/or death.
The shape of a patient's throat varies widely from one individual to the next. In some patients, the vocal cords can be seen on visual inspection and it is relatively easy to insert ah intubation device. However, in other patients, the vocal cords are completely hidden from view, making insertion of the intubation device difficult. Often it is helpful to extend the patient's head backward as far as possible to increase the medical practitioner's view of the vocal cords; but such an approach cannot be used if the patient has suffered a neck injury and has to be made immobile in order to prevent further damage.
In practice then, physical and anatomical variations among patients can make it difficult for a medical practitioner to clearly identify a particular individual's vocal cords. Unless they can be properly identified, however, they may be damaged during ah intubation procedure. To address this heed, Schwartz et al. (U.S. Pat. No. 6,539,942) disclosed a tubular endotracheal device, capable of being flexed into a L-shape and through which a conventional imaging device, such as a nasopharyngoscope, is inserted centrally, so as to allow for direct visualization of the vocal cords.
Unfortunately, this prior art combination is too costly to be disposed of after a single patient use; and the probability of infectious materials being transmitted from one patient to another is high—especially during a medical emergency in which more than one airway-compromised patient is involved and the same imaging device must be reused immediately.